Rotary atomizing burner apparatus for liquid fuel



' Feb. 24, 1959 H. N. F. VERLOOP 2,874,757

ROTARY ATOMIZING BURNER APPARATUS FOR LIQUID FUEL.

Filed Aug. 2, 1955 .was

le 10a United States Patent ROTARY ATOMIZING BURNER APPARATUS FOR Y LIQUID FUEL Hendrik N. F. Verloop, Amsterdam, Netherlands Application AngustZ, 1955, Serial No. 525,996

Claims. (Cl. 158-77) The invention relates to a rotary atomizing burner apparatus for liquid fuel,A such as oil, of the kind comprising a substantially cup-shaped rotary atomizer member which is connected with a fuel supply means and whichis coaxially surrounded by a stationary air nozzle sleeve, the axially extending annular space comprised between the, atomizer member and the sleeve communieating with the pressure side of a rotary blower for forcing air through this annularspace outwardlyl towards lits axialz velocity has imparted to it a rotational movement in opposition to the direction of rotation of the atomizer member. Any such rotational movement of the air stream will, however, be counteracted by the atomizer member rotating in the opposite, direction` when the air '12,874,767 YPatented Feb. 24, 1959 2 follow the curvedvinner sleeve Wall whereby a strong whirling motion is obtained.

According to a preferred embodiment of the invention, in addition to the tangentially directed inlet ports the wall of the air nozzle sleeve is further provided with radially directed inlet ports likewise preferably having the form of axially extending slots, `a regulating valve sleeve being closely mounted on the air nozzle sleeve for rotary sliding movement thereabout which valve sleeve is provided with air passage openings adapted to cooperate with the respective inlet ports in the air nozzle sleeve and being shaped and positional in such a way that when by a turning movement of the valve sleeve the tangential inlet ports of the air nozzle sleeve are gradually closed,

will appear more fully from the following description v in conjunction with the Vaccompanying drawings whichV illustrates by way of example an embodiment of the invention. In the drawing Figure 1 is an axial section of the apparatus on the line `I-I of Figure 2;

passing through the relative narrow annular space between the air nozzle sleeve and thismember is made to ow for a `long'stretch along the outer wall thereof.

At lower `air speeds'this ybraking effect of the atomizer member could easily become so pronounced as to completely suppress the whirling motion originally impartedl v to the air. Y

It is accordingly'an object of the invention to solve this problem and to provide a rotary atomizing burner apparatus of the afore-mentioned kind inwhich a strong whirling motion in opposition to the rotational direction of the atomizer member can be imparted tothe air stream escaping4 from `the nozzle mouth. Another important object of the invention is to provide` novel 4means for regulating within wide limits the ,ratio between the rotational velocity and the axial velocity .of the air stream so as to make it possible to effectively controlthe shape of the burner llame Vand to adapt this llame to the form and dimensions of the combustion chamber. i

According to the invention, the `air delivered by the l blower isV forced into the annular space enclosed `between the atomizer member and the air nozzle sleeve through Y a numberV of tangentially directed` inlet ports provided in the `wall of this sleeve which inlet'lports preferably have the form of slots axially extending i-n the sleeve wall.

The air thus enters the annularspace sideways andina tangential direction, passing through the `slots in the sleeve wall directly opposite the sidewall of the atomizer member.

Thereby the air in moving towards the burner mouth is only for a short stretchsubjected ltoithe opposing rotational action of the Vatomizermember so that its initial whirling motion in thesleeve is but little weakened. Y

The air inlet ports opening tangentially in the annular space provide sharply pronounced tangential air streams which ongentering the air nozzle sleeve are forced to Figure 2 is an end view of the apparatus, partly a section on the line II-II of Figure 1 with the forward wallV of the casing removed; and

Figure 3 is a detail on an enlarged scale.

The apparatus illustrated in the drawing comprises a hollow shaft 1 adapted to be driven by an electric motor (not shown) and carrying on its outer. end a cup-shaped atomizer member 2 to which fuel oil can be fed -in the known manner from a supply system (not shown) through the bore of the hollow shaft 1 and a pipe 3 communicating with this bore.

The shaft 1 further carries `a fan 4 of a blower, the l hub of the fan being locked betweenva ring 5 on the shaft 1 on the one hand and a threaded sleeve member 6 i screwed on the threaded shaft end on the other hand.

This sleeve member projects forwardly and threadedly engages the base portion of the cup 2. The shaft 1 is mounted by a ball bearing 7 for rotation in a casing part 8 of the blower.

The blower casing consists of two parts bolted together, :i to wit: the rear part 8 having an air intake opening 9 and accommodating the fan 4, and the forward part 10 of substantially conical shape and ycomprising a flat baille plate 11 which extends radially directly in front of the fan 4 and has substantially the same radius as the latter. The two parts 8 and 10 of the blower casing are in communication with one, another through the annular l' opening 12 formed between the edge of the baille platey 11 and the rounded inner wall where the casing parts meet. The air forced radially outwardly Iby the fan `5 1 is thus made to pass around the edge of the bafe plate* 11 andlthence movesagain inwardlyftowards the cup 2 along arc-shaped vanes`13 xedly mounted inside VtheV f casing part 10 between the `baffle plate and the-forwardl wall i thereof. i

The baille plate I11 has a. threaded hub portion 411a coaxial with the shaft 1 which carries therthreaded inner i portion of an air nozzle sleeve 14 of cylindrical form.

The sleeve 14 coaxiallymsurrouuds the atomizer -cup l2 respect to the edge of the cup ZL The sleeve can be" locked in any desired position by means of `a removable stop 28 screwed to the outside of the casing part 10 and projecting with its forward end between any two of a number of equally spaced ribs 29 provided in a circle on`the outer wall of the sleeve 14.

The air nozzle sleeve 14 is provided with air inlet ports 16 and 17 which extend axially in the form of narrow slots opposite the side wall of the cup 2. The four ports 16A are tangentially directed with respect to the annular space 15 whereas the four narrower ports 17 are radially directed. On the outside of the sleeve the openings to the ports 16 and 17 are situated two and two directly adjacent one another. The forward and rear walls of the ports are inclined towards the burner mouth as is shown in Figure l for one of the ports 16.

Closely surrounding the sleeve 14 there has been provided a regulating valve sleeve 18 which can be turned about the sleeve 14 but is held against axial displacement between the baffle plate 11 and the shoulder of the rim portion 10a. The valve sleeve 18 has four slots 19 which on the inside correspond in size to the openings to the 2,374, vez

slots 16 and are equally spaced as the latter but have radially outwardly flaring side walls to facilitate the inflow of air. The valve sleeve 18 carries a fork 20 engaging a fork pin 21 on an arm 22 which is fixed to a shaft 23 rotatably mounted in the blower casing. One end of the shaft 23 projects outside the casingv and has fixed thereon a disc 24 provided with a mark which lies opposite a fixed scale 25 (see also Figure i).` By means of a key applied to 'a nut 26 lixed on the shaft 23 this shaft and thereby the valve sleeve 18 can be adjusted when the burner is in operation and the relative position of the valve sleeve can be read on the scale 25. By means of a locking bolt 27 engaging the disc 24 the valve sleeve can be fixed in any desired position.

In the position of the valve sleeve shown in Figure 1, the tangential ports 16 are completely open whereas the radial ports 17 are closed.V On rotation of the shaft 1 in the direction of the arrow 30 (Figure 2) the ow of l shape and position of the ports 19 with respect to the cup wall, the air ow on its way from the ports to the burner mouth is but little influenced by the rotation of the cup.

As a result the air leaves the burner mouth at the forward end of the space 15 with a strong whirling motion resulting in an excellent combustion and a relatively broad flame.

When the valve sleeve 18 is thereupon turned in anticlockwise direction into the position indicated with dotted lines in Figure 2, the tangential ports 16 are partly closed and simultaneously the radial ports 17 partly opened whereby the whirlingy motion is correspondingly diminished and a longer flame obtained.

By further turning the valve sleeve in anti-clockwise direction it can be adjusted to a position in which the air leaves the burner mouth practically without any whirling motion at all.

In this way the shape of the flame can be accurately adapted tothe required conditions and the form of the combustion chamber which adjustment can moreover be performed when the burner is in operation so that its elect on the flame can be directly checked. By axial adjustment of the sleeve 14 the shape of the flame can be'further modified.y

It will be clear that within the scope of the invention various modifications of the`described embodiment thereof may be resorted to. For instance, the ports 16 and 17 can be placed further apart in which case the slots 19 of the valve sleeve 18 have to be correspondingly wider so as to cover the distance between the corresponding side edges of two adjacent ports 16 and 17; alternately, the valve sleeve can also be provided with a separate slot for each port 16 and 17 if only these slots are so positioned that when by a turning movement of the valve sleeve the slots 16 are gradually closed, the slots 17 are Ysimultaneously gradually opened, or vice versa.

tween said rst-named inlet ports to provide a pluralityA of pairs of ports with each pair consisting of a tangentially-directed inlet port and a radially-directed inlet port, a regulating valve sleeve closely mounted on said air nozzle sleeve for rotary sliding movement on said air nozzle sleeve in both directions, said valve sleeve being provided with air passage openings adapted to cooperate with the respective pairs of inlet ports of said sleeve member and shaped 4and positioned in such a way that when upon rotation of the valve sleeve about the nozzle sleeve the tangential inlet ports of the sleeve member vare gradually closed and the radial inlet ports of the latter are gradually opened, and vice versa, and blower means for forcingair into said `annular space through the air passage openings of said valve sleeve and the air inlet ports of said sleeve member.

2. A rotary atomizing burner apparatus for liquid fuel, comprising a substantially cup-shaped rotary atomizer member adapted to "be driven for rotation in one direction, means for feeding fuel to said atomizer member, a stationary air nozzle sleeve member mounted coaxially Vabout said atomizer member and spaced therefrom to provide an axially extending 'annular space between said atomizer member and sleeve member terminating in an annular burner mouth between the forward rims of said two members, said sleeve member being provided with a plurality of vcircumferentially-spaced air inlet ports opening tangentiall'y'into said annular space in a direction against the directionof rotation of said atomizer member and with a plurality of circumferentially-spaced radially directed ports disposed in the spaces between said firstnamed inlet ports to provide a plurality of pairs of ports with eachpair consisting of a tangentially-directed inlet port and a radially-directed inlet port, said ports extending axially in the form of slots, a regulating valve sleeve closely surrounding said 'air nozzle sleeve member for rotary sliding movement on said air nozzle sleeve in both directions, meansrfor the manual adjustment of the angular position of said valve sleeve with respect to said air nozzle sleeve member, said valve sleeve being provided with air passage openings in thev form of `axially extending slots adapted to cooperate with the respective pairs of inlet ports of said sleeve member and shaped and positioned in such a way that when upon rotation of the valve sleeve the tangential inlet ports of the sleeve member are gradually closed, the radial inlet ports of the latter" are gradually opened, and vice versa, and blower means for forcing air into said annular space through the air passage openings of said valve sleeve and the air inlet portsI of said sleeve member.

3. A rotary atomizingV burner apparatus according to claim 2 in which the side WallsV of the air passage openings in said valve sleeve diverge in a radially outward direction with respect to the axis of said sleeve.

4. A rotary atomizing burner apparatus according to claim 2 in which inV relation to the outer wall of the air nozzle sleeve member a radially directed inlet port is situated directly adjacent each tangentially directed inlet port and in which said valve sleeve has a single air passage opening for each pair of `adjacent tangential and radial inlet ports, the width of said air passage opening substantially corresponding to the width of the tangential inlet port.

5. A rotary atomizing burner apparatus for liquid fuel, comprising a casing, a shaft mounted in said casing for rotation in one direction and having an axial bore, a substantially cup-shaped atomizer member i'lxedly mounted on the forward end of said shaft, means for feeding fuel to said atomizer member through the bore in said shaft, a fan inside said casing mounted on said shaft to the rear of said atomizer member, an air nozzle sleeve mounted in said casingcoaxially about said atomizer member and spaced therefrom to enclose an axially extending annular space between its inner wall and the atomizer member terminating in an annular burner mouth between the forward rims of said two members, said sleeve member being provided with a plurality of circumferentially-spaced air inlet ports opening tangentially into saidannular space in a direction against the direction of rotation of said atomizer member and with a plurality of circumferentially-spaced radially directed air inlet ports disposed in the spaces between said rst-named inlet ports to provide a plurality of pairs of ports with each pair consisting of a tangentially-directed inlet port and a radially-directed inlet port, said tangentially and radially directed ports both extending axially in the form of slots, aregulating Valve sleeve mounted in said casing and closely surrounding said air nozzle sleeve member for rotary sliding movement on Isaid air nozzle sleeve in both directions, regulating means adaptedto be manually operated from the outside of said casing for the adjustment of the angular position of said valve sleeve about said air nozzle sleeve member, said valve sleeve being provided with air passage p openings in the form of axially extending slots adapted to cooperate with the respective pairs of radially and tangentially directed inlet ports of said sleeve member and again towards the openings of said valve sleeve.

References Cited in the le of this patent UNITED STATES PATENTS 1,404,241 Simonides Jan. 24, 1922 1,406,739 Hurley Feb. 14, 1922 1,451,063 Anthony Apr. 10, 1923 1,490,861 Smith Apr. l5, 1924 1,594,686 Pease Aug. 3, 1926 1,602,364 Johnson Oct. 5, 1926 1,789,491 Mitchell Jan. 20, 1931 1,861,475 Hopkins June 7, 1932 2,174,663 Keller Oct. 3, 1939 2,202,822 Behrens June 4, 1940 2,218,643 Henriksen Oct. 22, 1940 2,357,587 Hammell Sept. 5, 1944 2,417,386 Titlestad Mar. 1l, 1947 FOREIGN PATENTS 440,811 Germany Aug. 24, 1924 

